Violectric DHA V590² Pro Headphone Amplifier, Preamp, and DAC - Manual (Page 24)

24
Filter curves (taken from the data sheet of AK4490)
Sharp Roll-off Filter / Long Delay
Sharp Roll-off Filter / Short Delay (Werkseinstellung / Default)
Slow Roll-off Filter / Long Delay
Slow Roll-off Filter / Short Delay